Abstract:
Shoreline evolution is a critical issue of coastal zone resource management and sustainable development. Influenced by both natural processes and human activities, the coastline of the Yellow River Delta (YRD) has persistently undergone rapid changes. We investigated the dynamic evolution patterns of the YRD coastline over the past 48 years (1976 to 2024) and its response to extreme weather events by using Landsat series and GF-1 satellite imagery of the YRD and the Digital Shoreline Analysis System (DSAS). Results demonstrate that the evolution of the YRD coastline showed a trend of sediment accretion by an average annual increase in land area of 6.358 km2. Furthermore, the evolution displays distinct phase-specific characteristics, which can be categorized into three typical stages: (1) Rapid deposition stage (1976 to 1988, maximum rate of 1825 m/a in coastline length); (2) The whole erosion stage (1989 to 2008, the maximum rate of 1243 m/a); (3) Local effective siltation stage (after 2009, the current estuary siltation rate from 2016 to 2024 was 320 m/a). The sediment flux into the sea was the dominant controlling factor of shoreline evolution. Human activities directly shaped the accretion-erosion pattern by regulating the seasonal distribution of water and sediment, while extreme events significantly promoted the erosion under low-sediment conditions. Moreover, the impact of extreme events on the coastline showed pronounced spatial heterogeneity: exposed shorelines experienced heavy erosion, and some areas demonstrated recovery potential due to sediment replenishment. We elucidated the comprehensive response characteristics of the YRD coastline, which was characterized by "phase-specific instability, strong spatial heterogeneity, and localized resilience". These findings provided an important scientific basis for sustainable management and adaptive regulation strategies for this highly dynamic delta.